I send out my bigger stuff for blasting to a company that does powder coating they will burn off the old finish before they blast it so there really isnt a worry of grease or the wrong media used etc -- but you still have to blow out all the blasting dust from all holes once thats done clean it with denatured alcohol and just to be on the safe side of things I do pre cook or do a burn-out how ever you wanna call it JUST to make 100% sure there is nothing to mess with the powder--burn out usually 50 degrees or so above the actual part temp for a longer period--then look it over really well again before powder --- powder it on up, cook it, let it 100% cool, spray coat #2 and cook it again times/heat etc will vary but as an example the above superchrome cures at 12 minutes Part Temp at 380*(and chrome powder is sensitive to the cure cycle) second coat yellow cures out at 400 for 10--BUT unlike other powders the chrome has to fully cure out before the top coat and your top coat has to cure at the same temp as the chrome no matter what its cure temp is so that means you drop the yellows heat to 380 and extend cook time--> again from Part temp thats the fast easy version lol (usually on second coats its a half to 3/4 cure then second coat it and do a normal full cure for the second coat again powder to powder things may be different)----dont know your current set-up, if any, but if your gonna try and powder a whole frame with an eastwood/harbor freight type gun you better stick with 1 coat
Edit---I used less than 1# of powder on each with my set-up and spraying-- you could use more or less but i think youd be safe ordering 1# base and 2# top coat cause if you have problems it will be on that second coat and its just better to have more than less
